Pyrotechnical flare charges, for instance such as are included in parachute flares, are normally provided with external insulation which covers all sides of the flare charge apart from that side which is to be aligned at the target area in question. In this manner, a controlled combustion of the flare charge will be obtained, and the flame is prevented from damaging the parachute disposed above the flare charge. The best possible results will be attained if the properties of the insulation are such that the insulation proper is combusted at the same rate as, or slightly slower than the remainder of the flare charge. Insulation which is too readily combustible will give rise to a total flash-over and rapid flare ignition, with consequently insufficient burning time.
This art has previously seen the employment of different types of thermosetting resin insulations, for example epoxy insulations with coolant and filler additives in the form of, for example, CaCO.sub.3 and also asbestos. In order to function as an adequate flare charge insulation, this must first satisfy the requirements of suitable combustion rate, and secondly give the best possible light yield. At the same time, it should not, during its combustin, generate soot or smoke which may obscure or disrupt the flame. One disadvantage which is particularly manifest in the epoxy-based flare charge insulations is that the epoxy group, which is biologically active, is--with all justification--considered as a serious health hazard during the manufacturing phase.
Prior art types of thermosetting resin-based flare charge insulations have been applied to the ready-pressed flare charges by casting in a mould adapted for this purpose. Now that the flare charge insulation according to the present invention has been produced as a semi-manufacture in the form of a fine-grained granulate and not as a castable liquid, the novel flare charge insulation material has entailed requirements of new method for manufacturing the finished flare charge with its associated insulation. Hence, the present invention relates not only to the basic material for a novel type of flare charge insulation, but also to a novel method of producing a pyrotechnical flare charge provided with this novel type of flare charge insulation, and finally, also the finished flare charge with its associated insulation.